Electrode assembly



Aug. 1, 1939. J. R. GLANS ELECTRODE ASSEMBLY Filed June 50, 1938 sijlH H1 1 INVENTOR. JSEPH R. GLANS. 7 BY 4 fl/ aw/ ATTORNEY.

Patented Aug. 1, 1939 PATENT OFFICE 2,167,885 ELECTRODE ASSEMBLY Joseph R. Glans, Bloomfield, N. J., assignor, by mesne assignments, to Radio Corporation of America, New York, N. Y., a corporation of Delaware Application June 30, 1938, Serial No. 216,685

, 4 Claims.

My invention relates to electrode, assemblies for electron, discharge devices, particularly'to means forihountin'gplatelike electrodes, such as anodes, in the devices.

The conventional electrode assembly comprises a cathode surrounded by concentric grid and anode electrodes, and a flat spacing member such as a sheet of mica across each end of the assembly to hold the electrodes in insulated spaced relation. To join the electrodes and the spacers, electrode extensions, such as side rods on the grids and ears or lugs on the anodes, are commonly inserted in holes in the mica spacers and locked in place. The usual electrode extensions are difficult to thread into place and add materially to the cost of assembling. Further the extensions are usually sharp edged and cut into the side of the spacer holes when inserted, thus enlarging the holes so that movement of the electrodes and troublesome microphonic noises in the finished tube may occur, and accurate centering of the electrodes is difficult.

An object of my invention is an electrode assembly for electron discharge devices which is easy to assemble, which is rigid in construction and inexpensive to manufacture.

The characteristic features of my invention are defined in the appended claims and the preferred embodiment is described in detail in the following specification and shown in the accompanying drawing in which Figure l is a sectioned radio tube showing in elevation an electrode assembly constructed according to my invention, Figure 2 is a detailed perspective View of an anode electrode constructed according to my invention, and Figure 3 is a side elevation partly in section of an anode constructed according to my invention.

The electron discharge device selected for illustrating my invention comprises a metal envelope I, closed at its lower end with a disc-like press of glass 2, containing lead-in conductors joined at their lower ends to contact pins in the base of the device. The electrode assembly comprises the cathode 3, a wire wound grid on side rods 4, and anode 5 joined at their ends to plate-like insulating spacers 6. The lower spacer rests upon offset shoulders in support rod 1 rising from the header and the upper spacer is held against the end of the anode by tabs welded to the upper ends of the support rods. The ends of cathode 3, side rods 4 and ear extensions 8 on the fins 9 of the anode are threaded through holes in the spacers and the entire assembly lowered on to the support rods 1, lengthwise displacement of the anode being prevented by shoulders [0, Figure 2, on the ends of the anodes whichbear against the opposed faces of the two spacers. The electrodes are thuseffectively clampedi'n place between the support rod shoulders and the metal tabs.

To insure accurate spacing between the cylindrical portion II of the anode and the included grid and cathode I provide according to my invention novel means for guiding the anode into place and for firmly holding the anode against lateral displacement. The anode is conveniently pressed from sheet metal, such as nickel, to form the cylindrical or barrel portion H with two oppositely extending fins 9, the ends of the fins extending axially beyond shoulders Ill. In each ear is pressed an embossing or bead I2. The corresponding openings in the mica to receive the ears are elongated slots of substantially the same width as the thickness of the ears. The length of each slot, however, is greater than the width of the ear and the side of the slot is cut out with a semicircular recess M to receive the embossings I2. The rounded end of the embossing facilitates the insertion of the ear into its slot and prevents the cutting or digging away of the slot edges. To wedge the ear in place, the embossings may be tapered in an axial direction so that the width and height of the embossing is less at its outer end.

In assembly, the corner of one ear is inserted in the slot and the small end of the embossing of that ear slides into its recess l4, guiding the other ear on that end of the anode into its slot and the spacer and anode are pressed together bringing the spacer into contact with shoulder ill. The mean width and height of each embossing is slightly greater than the radius of its recess [4 so that when the spacer is pressed home the embossing lightly binds the ear in place. The distance between the center line of the anode and the center of the embossings may be accurately determined by the dies of the forming press, and the distance between the side rod and cathode holes in the spacer from the recess l4 may be accurately determined by the dies of the spacer punch press. Accordingly the radial spacing of the anode with its cooperating electrodes is accurately fixed by the machine dies of the presses and cannot be altered by an operator who may carelessly cut the ends of the slots [3 with the relatively sharp edges of the anode ears. The smooth rounded configuration of the embossings prevents fracturing of the spacer at the recesses.

Electrodes made according to my invention are easy to assemble, are firmly and accurately held in fixed spaced relation, are rugged in construction and are inexpensive to manufacture.

I claim:

1. An electrode assembly comprising a cathode and anode held in concentric fixed spaced relation by an insulating spacer transverse to the axis of the anode, the anode comprising a tubular portion with a radially extending fin, an ear extension on said fin for engaging a slot in said spacer, and 'means for preventing transverse movement of said ear in said slot, comprising an embossing integral with the fins on one side of said ear in registry with a recess in the side of said slot.

2. An electron discharge device comprising an electrode, a flat ear extending from said electrode,

means for fixedly supporting said electrode com- 3. An electrode assembly comprising a plurality of concentric electrodes, an insulating spacer transverse to the axis of the electrodes for holding the electrodes in concentric spaced relation,

a fiat ear extension on one of said electrodes ex- 5 tending through a slot in said spacer, and means for centering said ear extension in the slot comprising a tapered embossing on' the ear in registry with a recess in the side 01' said slot.

4. An electrode assembly comprising a tubular 1o anode and a concentric cathode, an insulating spacer joined to the ends 01' the electrodes, a

shoulder on the end of said anode adapted to hold said spacer normal to the anode axis, and longitudinal fins extending radially from the wall ,of 15 

